"""

gadict dictionary format parser.

"""

import regex

class Prelude:

    """Dictionary metainfo structure."""

    name = None

    about = ""

    urls = []

    authors = []

    licences = []

class ParseException(BaseException):

    def __init__(self, msg, lineno=None, line=None):

        super().__init__()

        self.msg = msg

        self.lineno = lineno

        self.line = line

    def __repr__(self):

        if self.lineno is None:

            return self.msg

        elif self.line is None:

            return ":{:d}:{:s}".format(self.lineno, self.msg)

        else:

            return ":{:d}: {:s}\nLINE: {:s}".format(self.lineno, self.msg, self.line)

class Parser:

    """gadict dictionary format parser."""

    COMMENT_RE = regex.compile(r"^# ")

    SEPARATOR_RE = regex.compile(r"^__$")

    HEADWORD_RE = regex.compile(r"^(\p{L}.*)$")

    HEADWORD_PRON_RE = regex.compile(r"^ +\[([\p{L}' ]+)\]$")

    TRANSL_POS_RE = regex.compile(r"^n|pron|adj|v|adv|prep|conj|num|int|phr|phr\.v|abbr|prefix$")

    TRANSL_RE = regex.compile(r"^(ru|uk|la|en): ([\p{L}(].*)$")

    TRANSL_EX_RE = regex.compile(r"^(ru|uk|la|en)> (\p{L}.*)$")

    TOPIC_RE = regex.compile(r"^topic: (\p{L}.*)$")

    CONT_RE = regex.compile(r"^ +(.*)")

    TRAILING_SPACES_RE = regex.compile(r"\p{Z}+$")

    PRELUDE_NAME_RE = regex.compile(r"^name: (.*)")

    PRELUDE_URL_RE = regex.compile(r"^url: (.*)")

    PRELUDE_AUTHOR_RE = regex.compile(r"^by: (.*)")

    PRELUDE_LICENSE_RE = regex.compile(r"^term: (.*)")

    PRELUDE_ABOUT_RE = regex.compile(r"^about: ?(.*)")

    def __init__(self):

        pass

    def readline(self):

        while True:

            self.line = self.stream.readline()

            self.eof = len(self.line) == 0

            if not self.eof:

                self.lineno += 1

            if self.TRAILING_SPACES_RE.search(self.line):

                raise ParseException("Traling spaces detected...\n")

            if self.COMMENT_RE.search(self.line):

                continue

            break

    def parse(self, stream):

        self.lineno = 0

        self.stream = stream

        self.dom = []

        try:

            self.parse_prelude()

            while not self.eof:

                self.parse_article()

        except ParseException as ex:

            raise ParseException(ex.msg, self.lineno, self.line)

        return self.dom

    def parse_prelude_continuation(self):

        string = ""

        while True:

            self.readline()

            if self.eof:

                return string

            m = self.CONT_RE.match(self.line)

            if m is not None:

                string += "\n" + m.group(1)

            elif len(self.line) == 1:

                string += "\n"

            else:

                return string

    def parse_prelude(self):

        """Read dictionary prelude until first "__" delimiter."""

        pre = Prelude()

        while True:

            self.readline()

            if self.eof:

                raise ParseException("There are no articles...")

            m = self.PRELUDE_ABOUT_RE.match(self.line)

            if m:

                pre.about += m.group(1) + self.parse_prelude_continuation()

                if self.eof:

                    raise ParseException("There are no articles...")

            if self.SEPARATOR_RE.match(self.line):

                break

            m = self.PRELUDE_NAME_RE.match(self.line)

            if m:

                pre.name = m.group(1)

                continue

            m = self.PRELUDE_URL_RE.match(self.line)

            if m:

                pre.urls.append(m.group(1))

                continue

            m = self.PRELUDE_AUTHOR_RE.match(self.line)

            if m:

                pre.authors.append(m.group(1))

                continue

            m = self.PRELUDE_LICENSE_RE.match(self.line)

            if m:

                pre.licences.append(m.group(1))

                continue

        self.dom.append(pre)

    def parse_article(self):

        """Try to match article until next "__" delimiter. Assume that `self.line` point to "__" delimiter."""

        self.words = None

        self.tran = None

        self.parse_empty_line()

        self.parse_headlines()

        self.parse_translation()

        self.dom.append((self.words, self.tran))

    def parse_empty_line(self):

        self.readline()

        if self.eof or len(self.line) != 1:

            raise ParseException(""""__" delimiter should followed by empty line...""")

    def parse_headlines(self):

        """Try to match word variations with attributed. Assume that `self.line` on preceding empty line."""

        self.words = {}

        self.readline()

        if self.eof:

            raise ParseException("""There are no definition after "__" delimiter...""")

        m = self.HEADWORD_RE.match(self.line)

        if m is None:

            raise ParseException("""There are no headword after "__" delimiter...""")

        word = m.group(1)

        pron = None

        attrs = set()

        while True:

            self.readline()

            if self.eof or len(self.line) == 1:

                break

            m = self.HEADWORD_RE.match(self.line)

            if m is not None:

                if word is None:

                    raise ParseException("""Didn't match previous headword...""")

                self.words[word] = (pron, attrs)

                word = m.group(1)

                pron = None

                attrs = set()

                continue

            m = self.HEADWORD_PRON_RE.match(self.line)

            if m is not None:

                if pron is not None:

                    raise ParseException("""Pronunciation is redefined...""")

                pron = m.group(1)

                continue

            m = self.HEADWORD_VAR_RE.match(self.line)

            if m is not None:

                attrs.add(m.group(1))

                continue

            raise ParseException("""Line is not a headword or translation or headword attribute...""")

        self.words[word] = (pron, attrs)

    def parse_translation_continuation(self):

        string = ""

        while True:

            self.readline()

            if self.eof:

                return string

            m = self.CONT_RE.match(self.line)

            if m is not None:

                string += "\n" + m.group(1)

            else:

                return string

    def parse_translation(self):

        senses = []

        pos = None

        tr = []

        ex = []

        read = True

        while True:

            if read:

                self.readline()

            read = True

            if self.eof:

                break

            m = self.SEPARATOR_RE.match(self.line)

            if m is not None:

                break

            if len(self.line) == 1:

                senses.append((pos, tr, ex))

                pos = None

                tr = []

                ex = []

                continue

            m = self.TRANSL_POS_RE.match(self.line)

            if m is not None:

                if pos is not None:

                    raise ParseException("""Each translation should have only one part of speech marker...""")

                pos = m.group(0)

                continue

            m = self.TOPIC_RE.match(self.line)

            if m is not None:

                # TODO

                continue

            m = self.TRANSL_RE.match(self.line)

            if m is not None:

                tr.append((m.group(1), m.group(2) + self.parse_translation_continuation()))

                read = False

                continue

            m = self.TRANSL_EX_RE.match(self.line)

            if m is not None:

                ex.append((m.group(1), m.group(2) + self.parse_translation_continuation()))

                read = False

                continue

            raise ParseException("""Uknown syntax...""")

        if len(tr) > 0:

            senses.append((pos, tr, ex))

        self.tran = senses